Fixed IRMutator::visit(FunctionDecl *).
Fixed IRMutator::visit(FunctionDecl *).


Former-commit-id: 63834784eb16f89b4b45032215530ec662bf7ac3
darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide